This invention relates to a disc brake for vehicles such as automobiles and, more particularly, to an improved pin type floating caliper disc brake wherein the braking torque is transmitted directly to the vehicle through the pins.
One type of disc brake assembly known in the prior art includes a sliding caliper which is mounted to straddle a disc. An outboard brake pad, mounted on the caliper outboard leg, engages the outer friction surface of the rotating disc. The caliper inboard leg includes a hydraulic piston which, when actuated, presses an inboard brake pad against the inner friction surface of the disc. At the same time, the caliper slides so that an equal and opposite force is applied by the outboard pad to the disc, thereby causing a braking action. When the hydraulic pressure is removed from the piston, the brake pads will drag along the disc. Ideally, the brake pads will float slightly away from the disc surface so that limited friction occurs. Any drag between the disc and the brake pads reduces the efficiency of the vehicle and causes premature wearing of the pads. The support pins in prior art brakes are normally mounted either on the caliper assembly or, in the case of a floating caliper disc brake, the pins are mounted on an anchor plate. The anchor plate being rigidly attached to the vehicle structure. In the case of steerable wheels, the anchor plate is attached to the wheel spindle and in the case of non-steerable wheels, the anchor plate is attached to the vehicle frame or some other frame member which is suspended with the wheels. In either case, the anchor plate is undesirable since it adds considerable weight both to vehicle and to the wheel suspension. This in turn requires the use of heavier suspension components for the wheels.